On-Line Collision Avoidance of Mobile Robot for Dynamically Moving Obstacles

Abstract

This paper proposes a realistic on-line navigation method of mobile robot in dynamical environment where multiple obstacles (many people) are always changing their velocities and the robot does not know the velocities in advance. Considering characteristics of actual sensor system for mobile robot, a method to estimate the velocity of moving obstacles is presented. The estimated velocity and measured distance from the nearest obstacle are used to plan a velocity of mobile robot based on a new idea of Collision Possibility Cone. Then an on-line navigation method is proposed by using Collision Possibility Cone and feasible velocity space of mobile robot. By considering the dynamical constraints of mobile robot and moving obstacles, the mobile robot using the navigation method can move to it’s destination without collision in the existence of multiple moving obstacles, even for the case that the moving obstacles change their velocities between sensor cycle of mobile robot. Simulational examples of on-line navigation show an effectiveness of the new navigation method. Finally a developed mobile robot to demonstrate the usefulness of the proposed method is shown.